Herrick and Johnston, both researchers at the UW arboretum, want to test one of the few promising weapons against jumping worms: a low-nitrogen fertilizer called Early Bird, commonly used on golf courses. To assess its effectiveness, they’ve been manually removing all the worms from each of 24 high-walled rings before adding back a known number of victims. (When I ask Herrick what they do with the evicted worms, he says, “We gently chuck them.”)